<!doctype html>
<meta charset="utf-8">
<title>Test for AudioBuffer's "acquire the content" operation</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script>
const SAMPLERATE = 8000;
const LENGTH = 128;

var tests = {
  "AudioBufferSourceNode setter set with non-null buffer": function(oac) {
    var buf = oac.createBuffer(1, LENGTH, SAMPLERATE)
    var bs = new AudioBufferSourceNode(oac);
    var channelData = buf.getChannelData(0);
    for (var i = 0; i < channelData.length; i++) {
      channelData[i] = 1.0;
    }
    bs.buffer = buf;
    bs.start(); // This acquires the content since buf is not null
    for (var i = 0; i < channelData.length; i++) {
      channelData[i] = 0.5;
    }
    allSamplesAtOne(buf, "reading back");
    bs.connect(oac.destination);
    return oac.startRendering();
  },
  "AudioBufferSourceNode buffer setter set with null" : (oac) => {
    var buf = oac.createBuffer(1, LENGTH, SAMPLERATE)
    var bs = new AudioBufferSourceNode(oac);
    var channelData = buf.getChannelData(0);
    for (var i = 0; i < channelData.length; i++) {
      channelData[i] = 1.0;
    }
    bs.buffer = null;
    bs.start(); // This does not acquire the content
    bs.buffer = buf; // This does
    for (var i = 0; i < channelData.length; i++) {
      channelData[i] = 0.5;
    }
    allSamplesAtOne(buf, "reading back");
    bs.connect(oac.destination);
    return oac.startRendering();
  },
  "ConvolverNode": (oac) => {
    var buf = oac.createBuffer(1, LENGTH, SAMPLERATE)
    var impulse = oac.createBuffer(1, 1, SAMPLERATE)
    var bs = new AudioBufferSourceNode(oac);
    var convolver = new ConvolverNode(oac, {disableNormalization: true});

    impulse.getChannelData(0)[0] = 1.0; // unit impulse function
    convolver.buffer = impulse; // This does acquire the content
    impulse.getChannelData(0)[0] = 0.5;

    var channelData = buf.getChannelData(0);
    for (var i = 0; i < channelData.length; i++) {
      channelData[i] = 1.0;
    }
    bs.buffer = buf;
    bs.start();

    bs.connect(convolver).connect(oac.destination);
    return oac.startRendering();
  }
};

function allSamplesAtOne(audiobuffer, location) {
  var buf = audiobuffer.getChannelData(0);
  for (var i = 0; i < buf.length; i++) {
    // The convolver can introduce a slight numerical error.
    if (Math.abs(buf[i] - 1.0) > 0.0001) {
      assert_true(false, `Invalid value at index ${i}, expected close to 1.0, found ${buf[i]} when ${location}`)
      return Promise.reject();
    }
  }
  assert_true(true, `Buffer unmodified when ${location}.`);
  return Promise.resolve();
}

for (const test of Object.keys(tests)) {
  promise_test(async function(t) {
    var buf = await tests[test](new OfflineAudioContext(1, LENGTH, SAMPLERATE));
    return allSamplesAtOne(buf, "rendering");
  }, test);
};
</script>
